Recently a lot of attention has been drawn to build dark energy model in which the equation-of-state parameter w can cross the phantom divide w = -1 .
One of models to realize crossing the phantom divide is called quintom model , in which two real scalar fields appears , one is a normal scalar field and the other is a phantom-type scalar field .
In this paper we propose a non-canonical complex scalar field as the dark energy , which we dub “ hessence ” , to implement crossing the phantom divide , in a similar sense as the quintom dark energy model .
In the hessence model , the dark energy is described by a single field with an internal degree of freedom rather than two independent real scalar fields .
However , the hessence is different from an ordinary complex scalar field , we show that the hessence can avoid the difficulty of the Q-ball formation which gives trouble to the spintessence model ( An ordinary complex scalar field acts as the dark energy ) .
Furthermore , we find that , by choosing a proper potential , the hessence could correspond to a Chaplygin gas at late times .